| 초록 |
The aim of this work is revealing the structure of lignin and structure-depended depolymerization behaviors of six types of lignin produced from oakwood (hardwood) and pinewood (softwood) by different lignin isolation methods (ethanolsolv (E), formasolv (F) and klason (K) process). The amount of ether bond was confirmed by nitrobenzene oxidation and FI-IR analysis, and the results were in order of F ＞ E ＞ K. Supercritical ethanol with formic acid was used to depolymerize the lignin at varying temperatures to reveal lignin depolymerization behaviors. At 350 °C, almost full conversion (＞ 95%) and high bio oil yield (＞ 81 wt%) were achieved regardless of the lignin. On the other hand, at below 300 °C, lignin depolymerization is highly dependent on the lignin structure. At 300 °C, the formasolv lignin converted bio oil with high conversion (97%) and high bio-oil yield (86 wt%), while low conversion (34%) and low bio-oil yield (38 wt%) resulted in the conversion of klason lignin. |
